The BGS Lexicon of Named Rock Units — Result Details

Sron Garbh Semipelite Formation

Computer Code: SRGA Preferred Map Code: SG
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Gneissose semipelite with local gradations towards micaceous psammite. Typically magnetite-rich and hence notably magnetic. Thin amphibolites occur locally throughout.
Definition of Lower Boundary: Lower boundary not exposed. Probably tectonic boundary with Grampian Group rocks.
Definition of Upper Boundary: Where magnetite semipelite is succeeded (rapid / sharp transition) by tremolite schist of the Iubhair Beag Calcareous Formation.
Thickness: 0 - c. 400m.
Geographical Limits: Eastern part of Ardverikie Forest between the Allt Cam [NN 50 78] and the Allt Mhainisteir [NN 542 860]. On sheet 63E [Dalwhinnie].
Parent Unit: Lochaber Subgroup (DALO)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Area  Northern shoulder of Sron Garbh, Coire Cheap. 
Robertson, S and Mendum, J R, in press. Lithostratigraphy of the Grampian and Appin Groups in the Dalwhinnie district, sheet 63E, Scotland. British Geological Survey Technical Report. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: